I've seen every Star Trek episode two or three times, and I did not realize until this very moment that Sulu and Chekov are two different characters. Was one of them a replacement character for the other or something?

Sulu/Takei went on hiatus in season 2 to go off and make Green Berets 1968 so they brought in the Chekov character as replacement but then rehired Takei when the filming wrapped up. After he came back the two sorta shared the amount of lines of one character. Probably didn't help that Kirk went through the scripts and tried to steal all the best lines for himself and that the relationship between Kirk McCoy and Spock overshadowed the rest of the cast

Would really like to see an animated series of ST again. Was a huge fan of the original animated series and, of course, the Alan Dean Foster books of those shows in which you actually got more backstory.

But he's on the Enterprise, surely he must be the transporter chief; a really mischievous transporter chief by the look of his face! "I'll show Captain Kirk who's boss. I'll make sure he materializes on the planet with no pants on, in a room with just males!"

/If Star Trek: Captain Worf gets made, I want to see Andorian and Tellarite Starfleet officers!//they're the two other founding worlds of the United Federation of Planets!!

narkor:Canon went out the window in Voyager when they decided that the federation knew about the borg way before Q-Who - and that 7's parents went off in their cosmic winnebago looking for them. There is a discussion on one of the DVDs where the writers say "well this messes up canon" to which the Voyager showrunner said "screw canon, this is a good story"

It wasn't.

Anyway that probably marks the big people where Star Trek writers decided that they could deliberately break canon - rather than making mistakes as will happen from time to time.

There was no contact with the Borg before TNG, which lead to the Borg going back in time in an attempt to assimilate a less-advanced Earth. The wreckage of the borg sphere was reactivated by archeologists, and it created a mini-collective. Not so much a temporal ass-fark as Nero's arrival, but close.